[PATCH 3/5] iio: Add support for LMP92001 DAC

[s . abhisit]

From: Abhisit Sangjan <s.abhisit@xxxxxxxxx>

---
 drivers/iio/dac/Kconfig        |   9 ++
 drivers/iio/dac/Makefile       |   1 +
 drivers/iio/dac/lmp92001-dac.c | 350 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 360 insertions(+)
 create mode 100644 drivers/iio/dac/lmp92001-dac.c

diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
index 25bed2d..69d4ad3 100644
--- a/drivers/iio/dac/Kconfig
+++ b/drivers/iio/dac/Kconfig
@@ -310,4 +310,13 @@ config VF610_DAC
 	  This driver can also be built as a module. If so, the module will
 	  be called vf610_dac.
 
+config LMP92001_DAC
+        tristate "TI LMP92001 DAC Driver"
+        depends on MFD_LMP92001
+        help
+          If you say yes here you get support for TI LMP92001 DACs.
+
+          This driver can also be built as a module. If so, the module will
+          be called lmp92001_dac.
+
 endmenu
diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile
index 603587c..82395b6 100644
--- a/drivers/iio/dac/Makefile
+++ b/drivers/iio/dac/Makefile
@@ -33,3 +33,4 @@ obj-$(CONFIG_MCP4922) += mcp4922.o
 obj-$(CONFIG_STM32_DAC_CORE) += stm32-dac-core.o
 obj-$(CONFIG_STM32_DAC) += stm32-dac.o
 obj-$(CONFIG_VF610_DAC) += vf610_dac.o
+obj-$(CONFIG_LMP92001_DAC) += lmp92001-dac.o
diff --git a/drivers/iio/dac/lmp92001-dac.c b/drivers/iio/dac/lmp92001-dac.c
new file mode 100644
index 0000000..9ed4183
--- /dev/null
+++ b/drivers/iio/dac/lmp92001-dac.c
@@ -0,0 +1,350 @@
+/*
+ * lmp92001-dac.c - Support for TI LMP92001 DACs
+ *
+ * Copyright 2016-2017 Celestica Ltd.
+ *
+ * Author: Abhisit Sangjan <s.abhisit@xxxxxxxxx>
+ *
+ * Inspired by wm831x driver.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/iio/iio.h>
+#include <linux/mfd/core.h>
+#include <linux/platform_device.h>
+
+#include <linux/mfd/lmp92001/core.h>
+
+static int lmp92001_read_raw(struct iio_dev *indio_dev,
+                                struct iio_chan_spec const *channel, int *val,
+                                int *val2, long mask)
+{
+        struct lmp92001 *lmp92001 = iio_device_get_drvdata(indio_dev);
+        int ret;
+
+        switch (mask)
+        {
+        case IIO_CHAN_INFO_RAW:
+                switch (channel->type) {
+                case IIO_VOLTAGE:
+                        ret = regmap_read(lmp92001->regmap,
+                                        0x7F + channel->channel, val);
+                        if (ret < 0)
+                                return ret;
+
+                        return IIO_VAL_INT;
+                default:
+                        break;
+                }
+                break;
+        default:
+                break;
+        }
+
+        return -EINVAL;
+}
+
+int lmp92001_write_raw(struct iio_dev *indio_dev,
+                                struct iio_chan_spec const *channel,
+                                int val, int val2, long mask)
+{
+        struct lmp92001 *lmp92001 = iio_device_get_drvdata(indio_dev);
+        int ret;
+
+        if (val > 4095)
+                return -EINVAL;
+
+        switch (mask)
+        {
+        case IIO_CHAN_INFO_RAW:
+                switch (channel->type) {
+                case IIO_VOLTAGE:
+                        ret = regmap_write(lmp92001->regmap,
+                                        0x7F + channel->channel, val);
+                        if (ret < 0)
+                                return ret;
+
+                        return 0;
+                default:
+                        break;
+                }
+                break;
+        default:
+                break;
+        }
+
+        return -EINVAL;
+}
+
+static const struct iio_info lmp92001_info = {
+        .read_raw = lmp92001_read_raw,
+        .write_raw = lmp92001_write_raw,
+        .driver_module = THIS_MODULE,
+};
+
+ssize_t lmp92001_dvref_read(struct iio_dev *indio_dev, uintptr_t private,
+                        struct iio_chan_spec const *channel, char *buf)
+{
+        struct lmp92001 *lmp92001 = iio_device_get_drvdata(indio_dev);
+        unsigned int cref;
+        int ret;
+
+        ret = regmap_read(lmp92001->regmap, LMP92001_CREF, &cref);
+        if (ret < 0)
+                return ret;
+
+        return sprintf(buf, "%s\n", cref & 1 ? "external" : "internal");
+}
+
+ssize_t lmp92001_dvref_write(struct iio_dev *indio_dev, uintptr_t private,
+                         struct iio_chan_spec const *channel, const char *buf,
+                         size_t len)
+{
+        struct lmp92001 *lmp92001 = iio_device_get_drvdata(indio_dev);
+        unsigned int cref;
+        int ret;
+
+        if (strcmp("external\n", buf) == 0)
+                cref = 1;
+        else if (strcmp("internal\n", buf) == 0)
+                cref = 0;
+        else
+                return -EINVAL;
+
+        ret = regmap_update_bits(lmp92001->regmap, LMP92001_CREF, 1, cref);
+        if (ret < 0)
+                return ret;
+
+        return len;
+}
+
+ssize_t lmp92001_outx_read(struct iio_dev *indio_dev, uintptr_t private,
+                        struct iio_chan_spec const *channel, char *buf)
+{
+        struct lmp92001 *lmp92001 = iio_device_get_drvdata(indio_dev);
+        unsigned int cdac;
+        const char *outx;
+        int ret;
+
+        ret = regmap_read(lmp92001->regmap, LMP92001_CDAC, &cdac);
+        if (ret < 0)
+                return ret;
+
+        if (cdac & 1)
+                outx = "hiz";
+        else
+        {
+                if (cdac & 2)
+                        outx = "1 or dac";
+                else
+                        outx = "0 or dac";
+        }
+
+        return sprintf(buf, "%s\n", outx);
+}
+
+ssize_t lmp92001_outx_write(struct iio_dev *indio_dev, uintptr_t private,
+                         struct iio_chan_spec const *channel, const char *buf,
+                         size_t len)
+{
+        struct lmp92001 *lmp92001 = iio_device_get_drvdata(indio_dev);
+        unsigned int cdac, mask;
+        int ret;
+
+        if (strcmp("hiz\n", buf) == 0)
+        {
+                cdac = 1;
+                mask = 1;
+        }
+        else if (strcmp("dac\n", buf) == 0)
+        {
+                cdac = 0;
+                mask = 1;
+        }
+        else if (strcmp("0\n", buf) == 0)
+        {
+                cdac = 0;
+                mask = 3;
+        }
+        else if (strcmp("1\n", buf) == 0)
+        {
+                cdac = 2;
+                mask = 3;
+        }
+        else
+                return -EINVAL;
+
+        ret = regmap_update_bits(lmp92001->regmap, LMP92001_CDAC, mask, cdac);
+        if (ret < 0)
+                return ret;
+
+        return len;
+}
+
+ssize_t lmp92001_gang_read(struct iio_dev *indio_dev, uintptr_t private,
+                        struct iio_chan_spec const *channel, char *buf)
+{
+        struct lmp92001 *lmp92001 = iio_device_get_drvdata(indio_dev);
+        unsigned int cdac;
+        int ret;
+
+        ret = regmap_read(lmp92001->regmap, LMP92001_CDAC, &cdac);
+        if (ret < 0)
+                return ret;
+
+        return sprintf(buf, "%s\n", cdac & 4 ? "1" : "0");
+}
+
+ssize_t lmp92001_gang_write(struct iio_dev *indio_dev, uintptr_t private,
+                         struct iio_chan_spec const *channel, const char *buf,
+                         size_t len)
+{
+        struct lmp92001 *lmp92001 = iio_device_get_drvdata(indio_dev);
+        unsigned int cdac = 0;
+        int ret;
+
+        if (strcmp("0\n", buf) == 0)
+                cdac = 0;
+        else if (strcmp("1\n", buf) == 0)
+                cdac = 4;
+        else
+                return -EINVAL;
+
+        ret = regmap_update_bits(lmp92001->regmap, LMP92001_CDAC, 4, cdac);
+        if (ret < 0)
+                return ret;
+
+        return len;
+}
+
+static const struct iio_chan_spec_ext_info lmp92001_ext_info[] = {
+        {
+                .name = "vref",
+                .read = lmp92001_dvref_read,
+                .write = lmp92001_dvref_write,
+                .shared = IIO_SHARED_BY_ALL,
+        },
+        {
+                .name = "outx",
+                .read = lmp92001_outx_read,
+                .write = lmp92001_outx_write,
+                .shared = IIO_SHARED_BY_ALL,
+        },
+        {
+                .name = "gang",
+                .read = lmp92001_gang_read,
+                .write = lmp92001_gang_write,
+                .shared = IIO_SHARED_BY_ALL,
+        },
+        { },
+};
+
+#define LMP92001_CHAN_SPEC(_ch) \
+{ \
+        .channel = _ch, \
+        .scan_index = _ch, \
+        .type = IIO_VOLTAGE, \
+        .indexed = 1, \
+        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+        .ext_info = lmp92001_ext_info, \
+        .output = 1, \
+}
+
+static const struct iio_chan_spec lmp92001_dac_channels[] = {
+        LMP92001_CHAN_SPEC(1),
+        LMP92001_CHAN_SPEC(2),
+        LMP92001_CHAN_SPEC(3),
+        LMP92001_CHAN_SPEC(4),
+        LMP92001_CHAN_SPEC(5),
+        LMP92001_CHAN_SPEC(6),
+        LMP92001_CHAN_SPEC(7),
+        LMP92001_CHAN_SPEC(8),
+        LMP92001_CHAN_SPEC(9),
+        LMP92001_CHAN_SPEC(10),
+        LMP92001_CHAN_SPEC(11),
+        LMP92001_CHAN_SPEC(12),
+};
+
+static int lmp92001_dac_probe(struct platform_device *pdev)
+{
+        struct lmp92001 *lmp92001 = dev_get_drvdata(pdev->dev.parent);
+        struct iio_dev *indio_dev;
+        struct device_node *np = pdev->dev.of_node;
+        u8 gang = 0, outx = 0, hiz = 0;
+        unsigned int cdac = 0;
+        int ret;
+
+        indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*lmp92001));
+        if (!indio_dev)
+                return -ENOMEM;
+
+        iio_device_set_drvdata(indio_dev, lmp92001);
+
+        indio_dev->name = pdev->name;
+        indio_dev->modes = INDIO_DIRECT_MODE;
+        indio_dev->info = &lmp92001_info;
+        indio_dev->channels = lmp92001_dac_channels;
+        indio_dev->num_channels = ARRAY_SIZE(lmp92001_dac_channels);
+
+        of_property_read_u8(np, "ti,lmp92001-dac-hiz", &hiz);
+        cdac |= hiz;
+
+        of_property_read_u8(np, "ti,lmp92001-dac-outx", &outx);
+        cdac |= outx << 1;
+
+        of_property_read_u8(np, "ti,lmp92001-dac-gang", &gang);
+        cdac |= gang << 2;
+
+        ret = regmap_update_bits(lmp92001->regmap, LMP92001_CDAC, 7, cdac);
+        if (ret < 0)
+                return ret;
+
+        platform_set_drvdata(pdev, indio_dev);
+
+        return iio_device_register(indio_dev);
+}
+
+static int lmp92001_dac_remove(struct platform_device *pdev)
+{
+        struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+
+        iio_device_unregister(indio_dev);
+
+        return 0;
+}
+
+static struct platform_driver lmp92001_dac_driver = {
+        .driver.name    = "lmp92001-dac",
+        .driver.owner   = THIS_MODULE,
+        .probe          = lmp92001_dac_probe,
+        .remove         = lmp92001_dac_remove,
+};
+
+static int __init lmp92001_dac_init(void)
+{
+        return platform_driver_register(&lmp92001_dac_driver);
+}
+subsys_initcall(lmp92001_dac_init);
+
+static void __exit lmp92001_dac_exit(void)
+{
+        platform_driver_unregister(&lmp92001_dac_driver);
+}
+module_exit(lmp92001_dac_exit);
+
+MODULE_AUTHOR("Abhisit Sangjan <s.abhisit@xxxxxxxxx>");
+MODULE_DESCRIPTION("IIO DAC interface for TI LMP92001");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:lmp92001-dac");
-- 
2.7.4